DON'T SHARE YOUR NAIL FILE

Resist the urge to let anyone — even a relative — use your emery board. This tool is a porous germ-trapper. Keep yours to yourself, and replace it often.

DO WEAR THE RIGHT SHOE SIZE

Are you cramming your feet into too-small or too-pointy shoes? If so, your toenails may grow into the surrounding skin — causing the dreaded ingrown nail, which can lead to pain, swelling, and infection. When nails are too long, tight shoes can cause even more damage, says Mitchel P. Goldman, M.D., an associate clinical professor of dermatology at the University of California, San Diego. "If your toes hit the front of your shoe, nails can crack or turn black-and-blue. Or nails may lift, which can lead to infection."

DO MOISTURIZE DAILY

Nails need to be hydrated, since most problems crop up when they're parched. "Dry nails can crack, peel, and become brittle. Plus, dehydrated cuticles not only look ragged but also can turn into painful and infected hangnails," says Audrey Kunin, M.D., a Kansas City, Missouri, dermatologist. The best moisturizers are thick — even greasy. Try Elizabeth Arden Eight Hour Hand Cream.

DON'T GO BAREFOOT

Keep your shoes on while at public places (swimming pools, locker rooms, shoe stores) — if you don't, we won't be responsible for your toenail health. Why worry? "Warm, damp environments are a breeding ground for fungi and viruses," explains Phoebe Rich, M.D., a nail disorders expert and a clinical associate professor of dermatology at Oregon Health & Science University in Portland. Tip: If hose isn't offered when you're shoe shopping, ask for it.